1,720,955 research outputs found
CeO2/YSZ nanocomposite powders: reactivity towards CO oxidation
No full textThe reactivity of some CeO2/YSZ nanocomposite catalysts towards the CO oxidation was investigated.
The nanocomposite powders were prepared depositing, by wet impregnation, different
amounts of CeO2 on the yttria-stabilized zirconia (YSZ) surface. Transmission Electron Microscopy
analysis reveals that CeO2 grows as 3-D nanodimensional islands (ca. 4 nm) on the surface of
the supporting YSZ. The reactivity of the nanocomposite systems towards the CO oxidation rapidly
raises with increasing the amounts of CeO2 deposited on the YSZ
FTIR and solid-state NMR studies of octadecyl modified metal oxides obtained from different silane precursors
No full textOctadecyl (C18) modifiedmetal oxide substrates, including titania, zirconia, hafnia, and alumina, are prepared
using two types of silylating reagents, n-octadecyltrihydridosilane and n-octadecyltrichlorosilane.
Fourier transform infrared (FTIR) and solid-state 29Si nuclear magnetic resonance (NMR) measurements
are performed to examine the cross-linking of the silanes. Solid-state 13C NMR spectroscopy provides
information about the conformation and mobility of surface-immobilized alkyl chains. Variable temperature
FTIR investigations are carried out to study the influence of the organosilane precursors and
metal oxides on the conformational order of the alkyl modified systems. It is found that grafting by
means of n-octadecyltrichlorosilane yields higher grafting densities than surface modification with
n-octadecyltrihydridosilane. Combined pyridine adsorption and diffuse reflectance infrared Fourier transform
(DRIFT) measurements are performed on the titania and hafnia substrates to evaluate potential
surface heterogeneities, i.e. Lewis and Brønsted sites. Differences in the alkyl chain conformational order
within the series of C18 modified metal oxides are explained by the presence of island structures. The
reduced C18 conformational order for the samples grafted with n-octadecyltrihydridosilane is traced
back to the lower grafting density which in turn points to a lower reactivity of this silylating reagent. The
most striking result is the higher conformational order of the C18 chains grafted in the present surface
modified metal oxides when compared with silica-based systems. This finding is attributed to the lower
porosity of the metal oxide supports along with more closely packed chains on the surface
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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